Fig 1.
SPT—serine palmitoyltransferase, KDSR—3-keto-dehydrosphinganine reductase, CerS—ceramide synthase (various isoforms), DEGS—dihydroceramide desaturase (various isoforms), C1PP—ceramide-1-phosphate phosphatase, Acyl-CoA—fatty acyl coenzyme A, NADPH—nicotinamide adenine dinucleotide phosphate, reduced.
Fig 2.
Infusion protocol and the effects of intralipid and heparin or nicotinic acid infusion on plasma free fatty acids concentration and palmitate enrichment in rats.
(A)—outline of the infusion protocol; (B)–effect of intralipid and heparin infusion (n = 3 per group); (C)–effect of nicotinic acid infusion (n = 3 per group), (D)–plasma [U-13C]palmitate enrichment (n = 10 per group); C—control with phosphate buffered saline (PBS) infusion (grey circles); I+H—intralipid and heparin infusion (closed circles); NA—nicotinic acid infusion (grey circles). Values represent mean +/- SD.
Fig 3.
The impact of intralipid and heparin infusion or nicotinic acid infusion on plasma fatty acids, palmitate enrichment and insulin sensitivity parameters in rats.
(A)–total area under total plasma fatty acids concentration from Fig 2B and 2C (FFA AUC, n = 3 per group); (B)–total area under plasma palmitate enrichment from Fig 2D (MPE AUC, n = 10 per group); (C)–total plasma FFA concentration (n = 10); (D)–plasma palmitate turnover rate (n = 10); (E)–total plasma FFA turnover rate (n = 10); (F)–Plasma insulin (n = 10); (G)–Plasma glucose (n = 10); (H)–Estimation of homeostasis model assessment of insulin resistance (HOMA-IR; n = 10). C—control group; I+H—intralipid + heparin group; NA—nicotinic acid group. Values represent mean +/- SD; a—p<0.05 vs C, b—p<0.05 vs I+H.
Table 1.
The effect of intralipid and heparin or nicotinic acid infusion on rat individual plasma fatty acids concentration.
Fig 4.
The impact of intralipid and heparin infusion or nicotinic acid infusion on ceramide fractional synthesis rate and ceramide content in different rat muscles.
Panel A—ceramide fractional synthesis rate (CER FSR, n = 10); Panel B—total content of ceramide (CER, n = 10); C—control group; I+H—intralipid + heparin group; NA—nicotinic acid group. Values represent mean +/- SD; a—p<0.05 vs C, b—p<0.05 vs I+H.
Table 2.
The effect of intralipid and heparin or nicotinic acid infusion on ceramide molecular species in rat diaphragm, heart, soleus and white gastrocnemius muscle.
Fig 5.
The impact of intralipid and heparin infusion or nicotinic acid infusion on the content of sphingoid bases in different rat muscles.
Panel A—the content of sphinganine (SPA, n = 10); Panel B—the content of sphingosine (SPH, n = 10); C—control group; I+H—intralipid + heparin group; NA—nicotinic acid group. Values represent mean +/- SD; a—p<0.05 vs C, b—p<0.05 vs I+H.